[vasco]

> How do you test a medication that only needs to be taken once or twice? This is very challenging to study scientifically.

Most vaccines you only take once, you can still test if they work or not. Same with poison antidotes and things like that. Like I said, I'm not a doctor, but the fact that it's only once doesn't seem like the problem.

[thomastjeffery]

Yes, because you can measure the amount of antibodies as many times as you want; and you can be pretty certain they are the direct result of the vaccine.

How do you measure depression? How do you know what changed it, or how much?